A conventional door lock generally has an outer handle and an inner handle respectively and rotatably connected to the outside and the inside of the door so that the latch bolt can be retracted into the retractor of the lock by rotating either of the inner handle and the outer handle. When the lock is in a locked position, the outer handle cannot be rotated to retract the latch bolt. Nevertheless, people generally directly rotate the outer handle unintentionally even if the lock is locked so that the outer handle often incurs undesired torque. It is to be noted that when the lock is in a locked position, the outer handle is connected to the inner parts so that if the a large torque is applied to the outer handle, the related inner parts of the lock could be damaged.
The present invention intends to provide a lock which has a clutch mechanism which disengages the locking piece from the retaining base connected to the outer handle when the locking bar is pushed so that the outer handle is free to be rotated without actuating other parts in the lock. The clutch mechanism of the present invention involves a simple structure and resolves the inherent shortcomings of the conventional locks.